1. Field of Invention
This invention relates generally to a stopper for closing off an unused branching pipe in a main fluid supply line.
2. Brief Description of the Related Art
In many applications the need arises to close or seal off an unused branching pipe or T-connection in a main fluid supply line. For example, when a building is to be demolished or a site modified in such a way that gas supply to the site is no longer required, the T-connection that branches off from the main gas line to supply the site has to be sealed off. Heretofore, an access well had to be dug to the branching pipe or the T-connection. The access well had to be large enough for a man to descend into to access and seal off branching pipe or the T-connection. This process is very time consuming and expensive, requiring a considerable amount of excavation. The need persists in the art for a device that allows branching pipes, T-connections and the like to be closed off through a relatively small hole drilled into the ground to reach the buried branching pipe, T-connection or the like.
The present invention is directed to a self locking stopper and method of its use that allows the stopper to be inserted into a branching pipe through a relatively small bore hole. The self-locking stopper of the present invention includes a body having O-ring seals that is inserted into the branch pipe that is to be plugged. The self-locking stopper has outwardly biased locking tabs that are provided to engage a shoulder or step in the branching pipe in order to prevent the stopper from being pulled out, or pushed out by fluid pressure, once it is in place. The stopper system also includes a flanged insertion pipe used for inserting the stopper into the branch pipe. The stopper also has an adapter for engagement by an insertion tool that allows a user to insert the stopper from above ground.